Endocrine Abstracts

Introduction: Primary hyperparathyroidism is a common endocrine disease. Its association with inflammatory and thrombotic events was rarely reported in the literature. The pathophysiological mechanisms of this association remain uncertain. Herein, we report a case of hypercalcemia secondary to primary hyperparathyroidism revealed by a deep vein thrombosis.

Observation: A 65-year-old patient was referred to our department for primary hyperparathyroidism. The patient was admitted to the department of internal medicine for a deep vein thrombosis in the left lower limb. On physical examination, he had a body weight of 68 kg, a height of 165 cm, a body mass index of 24.9 kg/m², a blood pressure of 12/08 cmHg, and a heart rate of 57 beats/min. Other systemic and regional examinations did not show any abnormalities. Potential causes of vein thrombosis were excluded. Biological investigations showed a total calcium level of 3.3 mmol/l, a phosphorus level of 0.49 mmol/l, a creatinine level of 60.9 mmol/l, a PTH level of 163 ng/l, albumin level of 43 g/l, a 25 hydroxyvitamin D of 20.2 ng/ml, and a calciuria of 0.21 mmol/24 h. The diagnosis of primary hyperparathyroidism was established. Cervical ultrasound and Sestamibi scan showed a left inferior parathyroid nodule measuring 12.5 × 7 mm. Bone mineral density scan revealed osteoporosis. No other complications were observed. The patient was treated with saline intravenous hydration, zoledronic acid, and a therapeutic dose of low-molecular-weight-heparin. Then, he underwent a left inferior parathyroidectomy. The postoperative course was simple with a total calcium level of 2.25 mmol/l.

Discussion: Thrombotic events were reported in a few patients with primary hyperparathyroidism. This association may be explained by direct activation of prothrombotic factors and hemoconcentration. Even though hypercalcemia is a rare cause of thrombotic events, it should be considered in the clinical evaluation of patients with deep vein thrombosis in the absence of evident causes.